Auditory Processing Disorder (APD) is a disability whose prevalence and societal burden are unknown. The inability to accurately process auditory signals provides a challenge to learning and language acquisition, especially in crowded or noisy classrooms. There is abundant evidence in the scientific literature that in many cases APD coexists with, and may be the underlying cause of, a learning and/or language disability such as dyslexia, autism or specific language impairment (SLI). However, the association of APD and these heterogeneous language disorders is controversial. Since it is well-established that dyslexia, autism and SLI have hereditary components, the issue of the relationship between APD and these disorders might be addressed by determining whether APD is a heritable trait. We are collecting families in which one or more individual has been diagnosed with dyslexia, autism or SLI, and measuring the performance of all first degree relatives on tests of auditory processing. The comparisons of these quantitative auditory processing scores in four families recruited so far with those of normal controls is providing evidence that APD is a hereditary trait and may contribute to learning and language disabilities.